1. Field of the Invention
This invention is related to the air intermingling, interlacing, commingling, or bulking of yarns or yarn filaments with an air jet. More specifically this invention is related to an interlacing jet in which the yarn or yarn filaments are subjected to a turbulent air stream as the yarn or yarn filaments pass through a channel into which high pressure air is injected.
2. Description of the Prior Art
A number of air jet configurations are used to interlace or bulk multifilament yarns. Both closed jet and open jet configurations have been used in prior art applications. The following patents show some of the air jets or air jet inserts that have been used in applications where air is injected into a yarn channel transverse to the axis of the channel and to the yarn.
U.S. Pat. No. 5,146,660 discloses a device for air-bulking multifilament yarn. This device has a two piece body formed by a nozzle unit and a baffle unit that are attached to form a yarn channel. When yarn is inserted in this yarn channel through a threading slot, air is injected through the nozzle unit to intermingle the multifilament yarn. Thread guides in the form of glued-in sapphire pins are inserted in the nozzle unit at both ends of the yarn channel. These thread guides position the yarn to maintain a minimum distance from the nozzle section.
U.S. Pat. No. 5,010,631 also discloses an air nozzle with a continuous yarn channel with an open treading slot. A baffle wall section opposed to a nozzle wall section is configured so that the air stream deflected by the baffle wall section does not enter the threading slot. The stated purpose for this configuration is to prevent filaments and filament bundles from being carried along with the airstream so that they will not impinge upon the edges of the threading slot and be damaged.
European Patentschrift 0 564 400 B1 discloses a device for intermingling multifilament yarn in which opposite walls of a yarn channel are convexly curved so that the distance between the two wall surfaces gradually increases from a minimum at the outlet of a jet nozzle toward both ends of the yarn channel. Thread guides are positioned at both ends of the yarn channel and both thread guides are at the same elevation so that the yarn cannot follow the curved surface of the yarn channel and the position of the yarn relative to a threading slot remains essentially constant along the axis of the yarn channel.
U.S. Pat. No. 4,430,780 discloses a fluid flow commingling jet having a threading slot that extends substantially tangentially relative to the yarn channel. A fluid flow pin is mounted on a plate having yarn guide located at one end of the yarn channel. The position of the fluid flow pin alters the fluid flow characteristics of the jet to produce a forwarding action. A prior art closed jet with a tapered yarn channel to cause air to flow in the direction in which the thread is moving is also described.